John K. Van Pelt was born around 1841 in New Jersey to Henry Van Pelt. His father was a farmer who owned $4,000 of real estate and $500 of personal property by 1860. He enlisted in the Union army on September 1, 1862, and he mustered in as a private in Company K of the 30th New Jersey Infantry on September 17. The regiment took part in the Battle of Chancellorsville, and he mustered out on June 27, 1863.
He got married, and he had at least four children: Sadie, born around 1875; Harry, born around 1882; Jennette, born around 1884; and Albert, born around 1887. His wife probably died by the early 1890s, and he married Mary Thomas on April 26, 1893. They lived in Jersey City, New Jersey, and he worked as a wheelwright. He applied for a federal pension in December 1894 and eventually received one. He died of paralysis in Millstone, New Jersey, on February 8, 1914.